Southern California -- this just in

California's bullet train will cost an estimated $98.5 billion to build over the next 20 years, an amount far higher than any previous projection, according to a business plan scheduled to be unveiled Tuesday.

The estimate includes possible future inflation that will drive up the cost of the line, which would send trains at up to 220 mph from Southern California to the Bay Area.

The cost growth results in large part from a major revision in the construction schedule. In the past, the state assumed the system would be completed by 2020 but now assumes construction would be finished in 2033. That stretched-out schedule and an assumption that future inflation would average 3% per year are two key reasons the overall estimated cost of the system almost doubled in the new business plan.

In the past, the California High Speed Rail Authority has estimated the cost of the system would be $43 billion, based on construction being finished in 2020.

The California High Speed Rail Authority, the state agency running the project, plans to unveil the new business plan at a news conference Tuesday morning in Sacramento.

The authority’s past two plans have been sharply attacked, not only by opponents but many supporters, for offering unrealistic construction cost and ridership figures. The authority wants to begin construction next year and hopes to gain approval from the Legislature and Gov. Jerry Brown for appropriations from a bond issue that would build a $6.3-billion segment from Fresno to Bakersfield.

The price of the system has long been a moving target.

When the first business plan surfaced, it projected a $34-billion cost. By 2009, the estimate had jumped to $43 billion, in part because the authority included future inflation in the estimated cost of building the system over the next decade.

In August, the authority released two planning documents that signaled even higher costs. The cost of building only the first two segments in the Central Valley had jumped by as much as 100%, not including future inflation.